◆第一步：確認(rèn)數(shù)據(jù)庫的SCN變化:

SQL> col fscn for 9999999999999999999

SQL> col nscn for 9999999999999999999

SQL> select name,FIRST_CHANGE# fscn,NEXT_CHANGE# nscn,FIRST_TIME from v$archived_log;

...................

NAME FSCN NSCN FIRST_TIME

---------------------------- --------- -------------------

/mwarch/oracle/1_52413.dbf 12929941968 12929942881 2005-06-22 14:38:28

/mwarch/oracle/1_52414.dbf 12929942881 12929943706 2005-06-22 14:38:32

/mwarch/oracle/1_52415.dbf 12929943706 12929944623 2005-06-22 14:38:35

/mwarch/oracle/1_52416.dbf 12929944623 12929945392 2005-06-22 14:38:38

/mwarch/oracle/1_52417.dbf 12929945392 12929945888 2005-06-22 14:38:41

/mwarch/oracle/1_52418.dbf 12929945888 12929945965 2005-06-22 14:38:44

/mwarch/oracle/1_52419.dbf 12929945965 12929948945 2005-06-22 14:38:45

/mwarch/oracle/1_52420.dbf 12929948945 12929949904 2005-06-22 14:46:05

/mwarch/oracle/1_52421.dbf 12929949904 12929950854 2005-06-22 14:46:08

/mwarch/oracle/1_52422.dbf 12929950854 12929951751 2005-06-22 14:46:11

/mwarch/oracle/1_52423.dbf 12929951751 12929952587 2005-06-22 14:46:14

...................

/mwarch/oracle/1_52498.dbf 12930138975 12930139212 2005-06-22 15:55:57

/mwarch/oracle/1_52499.dbf 12930139212 12930139446 2005-06-22 15:55:59

/mwarch/oracle/1_52500.dbf 12930139446 12930139682 2005-06-22 15:56:00

NAME FSCN NSCN FIRST_TIME

------------------------- ------------- -----------

/mwarch/oracle/1_52501.dbf 12930139682 12930139915 2005-06-22 15:56:02

/mwarch/oracle/1_52502.dbf 12930139915 12930140149 2005-06-22 15:56:03

/mwarch/oracle/1_52503.dbf 12930140149 12930140379 2005-06-22 15:56:05

/mwarch/oracle/1_52504.dbf 12930140379 12930140610 2005-06-22 15:56:05

/mwarch/oracle/1_52505.dbf 12930140610 12930140845 2005-06-22 15:56:07

14811 rows selected.

◆此時(shí)的SCN為：

SQL> select dbms_flashback.

get_system_change_number fscn from dual;

FSCN

--------------------

12930142214

◆此時(shí)使用應(yīng)用用戶嘗試閃回

SQL> connect username/passWord

Connected.

◆現(xiàn)有的數(shù)據(jù):

SQL> select count(*) from hs_passport;

COUNT(*)

----------

851998

◆創(chuàng)建恢復(fù)表

SQL> create table hs_passport_recov

as select * from hs_passport where 1=0;

Table created.

◆此處選擇SCN向前恢復(fù)

SQL> select count(*) from hs_passport as of scn 12929970422;

COUNT(*)

----------

861686

◆嘗試多個(gè)SCN，獲取最佳值（注釋：如果可以得知具體時(shí)間，那樣則可以獲得準(zhǔn)確的數(shù)據(jù)閃回）

SQL> select count(*) from hs_passport as of scn &scn;

Enter value for scn: 12929941968

old 1: select count(*) from hs_passport as of scn &scn

new 1: select count(*) from hs_passport as of scn 12929941968

COUNT(*)

----------

861684

SQL> /

Enter value for scn: 12927633776

old 1: select count(*) from hs_passport as of scn &scn

new 1: select count(*) from hs_passport as of scn 12927633776

select count(*) from hs_passport as of scn 12927633776

*

ERROR at line 1:

ORA-01466: unable to read data - table definition has changed

SQL> /

Enter value for scn: 12929928784

old 1: select count(*) from hs_passport as of scn &scn

new 1: select count(*) from hs_passport as of scn 12929928784

COUNT(*)

----------

825110

SQL> /

Enter value for scn: 12928000000

old 1: select count(*) from hs_passport as of scn &scn

new 1: select count(*) from hs_passport as of scn 12928000000

select count(*) from hs_passport as of scn 12928000000

*

ERROR at line 1:

ORA-01466: unable to read data - table definition has changed

◆注意：最后選擇恢復(fù)到SCN為12929941968的時(shí)間點(diǎn)

SQL>

insert into hs_passport_recov

select * from hs_passport as of scn 12929941968;

861684 rows created.

SQL> commit;

Commit complete.

注釋：至此，則可以滿足需要，找回誤刪除的部分?jǐn)?shù)據(jù)，閃回恢復(fù)成功。